UHF波段无源雷达低仰角波瓣分裂现象分析及校正方法

针对低频段无源雷达低仰角远程预警探测时波瓣分裂影响俯仰向探测空域覆盖的问题,提出了一种波瓣分裂校正方法.首先分析了波瓣分裂形成原因和影响因素;然后基于阵列流型拟合思想,提出了一种利用最小二乘法求解变换矩阵的校正方法;最后通过仿真分析了角度量化间隔、角度变换区间对校正误差的影响,验证了校正方法的有效性.这对改进基于数字广播电视信号的无源雷达性能提供了参考.

Split liver transplantation: Current developments

In 1988, Rudolf Pichlmayr pioneered split liver transplantation(SLT), enabling the transplantation of one donor liver into two recipients-one pediatric and one adult patient. In the same year, Henri Bismuth and colleagues performed the first full right/full left split procedure with two adult recipients. Both splitting techniques were rapidly adopted within the transplant community. However, a SLT is technically demanding, may cause increased perioperative complications, and may potentially transform an excellent deceased donor organ into two marginal quality grafts. Thus, crucial evaluation of donor organs suitable for splitting and careful screening of potential SLT recipients is warranted. Furthermore, the logistic background of the splitting procedure as well as the organ allocation policy must be adapted to further increase the number and the safety of SLT. Under defined circumstances, in selected patients and at experienced transplant centers, SLT outcomes can be similar to those obtained in full organ LT. Thus, SLT is an important tool to reduce the donor organ shortage and waitlist mortality, especially for pediatric patients and small adults. The present review gives an overview of technical aspects, current developments, and clinical outcomes of SLT.

Increased expression of Notch1 in temporal lobe epilepsy: animal models and clinical evidence

Temporal lobe epilepsy is associated with astrogliosis. Notchl signaling can induce astrogliosis in glioma. However, it remains unknown whether Notchl signaling is involved in the pathogenesis of epilepsy. This study investigated the presence of Notchl, hairy and enhancer of split-l, and glial fibrillary acidic protein in the temporal neocortex and hippocampus of lithium-pilocar- pine-treated rats. The presence of Notchl and hairy and enhancer of split-1 was also explored in brain tissues of patients with intractable temporal lobe epilepsy. Quantitative electroencephalo- gram analysis and behavioral observations were used as auxiliary measures. Results revealed that the presence of Notchl, hairy and enhancer of split-l, and glial fibriUary acidic protein were en- hanced in status epilepticus and vehicle-treated spontaneous recurrent seizures rats, but remain unchanged in the following groups： control, absence of either status epilepticus or spontaneous recurrent seizures, and zileuton-treated spontaneous recurrent seizures. Compared with patient control cases, the presences of Notch1 and hairy and enhancer of split- 1 were upregulated in the temporal neocortex of patients with intractable temporal lobe epilepsy. Therefore, these results suggest that Notchl signaling may play an important role in the onset of temporal lobe epilepsy via astrogliosis. Furthermore, zileuton may be a potential therapeutic strategy for temporal lobe epilepsy by blocking Notchl signaling.

右半肝劈离式肝移植的简化“All in one”肝静脉重建方式的设计和临床应用

目的介绍右半肝劈离式肝移植时采用的简化“All in one”的肝静脉重建手术方式,探讨该术式的临床适应证、操作方式和预后。方法回顾性分析2例完全右半肝劈离式肝移植的病例资料,就右半肝肝静脉采用简化“All in one”重建方式进行总结分析。2例右半肝均为在体劈离,例1采用劈离肝实质至第一、二肝门,离断右肝管后整体灌注获取,台下分割肝脏血管的方法。例2采用在体劈离时先行获取左半肝,右半肝行在体灌注后获取。2例供肝劈离时均将肝中静脉主干保留于左半肝,右半肝的S5、S8段肝静脉采用同一供者髂动脉重建,并直接吻合于下腔静脉上原肝左和肝中静脉离断后的缺口,重建了肝后下腔静脉的完整性。结果采用简化“All in one”右半肝肝静脉重建方式,2例肝移植无肝期分别为41、36 min。肝脏开放后供肝回流良好,搭桥的髂动脉血管充盈满意,无肝脏淤血肿胀等表现,术后肝功能恢复顺利。分别随访1年11个月和10个月,无肝静脉和下腔静脉等流出道相关并发症发生。结论完全右半肝劈离式肝移植时,采用“All in one”的肝静脉重建方式可以简化移植肝脏流出道重建步骤、缩短无肝期时间,减少术后肝静脉并发症的发生。

中叶供肝肝移植的可行性动物实验研究

目的:探索肝中叶作为独立供肝进行移植的可行性,以进一步拓宽供肝来源。方法:普通级健康犬分成供体组(n=12,20～25 kg)和受体组(n=12,10～15 kg),供受体随机配对。供体手术将位于中央区的方叶、右中叶在体内劈离,原位灌注后保留其专属的门静脉中支、肝中动脉和中肝管,得到独立的中央区供肝并称重。受体手术先建立临时性门腔分流,供肝背驮式植入,流出口和腔静脉壁端侧吻合,供肝门静脉中支和受体门静脉主干行端端吻合后恢复新肝血流,重建动脉和胆管。术后观察受体腹腔及胆汁引流,每日检测肝功能,死亡后行尸检,移植物取标本行病理检查。结果:犬肝被深陷的叶间裂分隔成7叶,各叶间由较少的肝桥连接,方叶和右中叶由门静脉中支、中肝动脉营养血回流至肝中静脉,胆汁引流至中肝管。供体组体内劈离技术全部得以完成,手术时间(215.0±67.7)min,失血量(229.3±66.5)mL。比较GRWR,中央区供肝[(1.3±0.3)%]和假设的左侧区供肝的[(2.1±0.4)%]及右侧区供肝的[(0.9±0.1)%]之间差异均有统计学意义(均P<0.01)。受体组手术时间(327.6±75.3)min,无肝期(33.6±7.5)min,失血量(415.5±79.8)mL。12个供肝均成功植入,冷缺血时间为(41.9±12.1)min,(8.3±3.6)min后排泌胆汁。受体肝功能指标在术后第1天发生明显变化,随后逐渐恢复,中位存活时间92.5(18～272)h,未发现有因吻合口出血、血栓等外科技术性并发症而死亡受体。结论:犬动物模型证实肝中央区可以劈离出来作为一个独立的供肝器官,为将来拓宽供肝来源提供了另外一种思路。